1 files changed, 99 insertions, 0 deletions
diff --git a/botan/src/mac/hmac/hmac.cpp b/botan/src/mac/hmac/hmac.cpp
new file mode 100644
index 0000000..717e264
--- /dev/null
+++ b/botan/src/mac/hmac/hmac.cpp
@@ -0,0 +1,99 @@
+/*
+* HMAC
+* (C) 1999-2007 Jack Lloyd
+*     2007 Yves Jerschow
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/hmac.h>
+#include <botan/xor_buf.h>
+
+namespace Botan {
+
+/*
+* Update a HMAC Calculation
+*/
+void HMAC::add_data(const byte input[], u32bit length)
+   {
+   hash->update(input, length);
+   }
+
+/*
+* Finalize a HMAC Calculation
+*/
+void HMAC::final_result(byte mac[])
+   {
+   hash->final(mac);
+   hash->update(o_key);
+   hash->update(mac, OUTPUT_LENGTH);
+   hash->final(mac);
+   hash->update(i_key);
+   }
+
+/*
+* HMAC Key Schedule
+*/
+void HMAC::key_schedule(const byte key[], u32bit length)
+   {
+   hash->clear();
+   std::fill(i_key.begin(), i_key.end(), 0x36);
+   std::fill(o_key.begin(), o_key.end(), 0x5C);
+
+   if(length > hash->HASH_BLOCK_SIZE)
+      {
+      SecureVector<byte> hmac_key = hash->process(key, length);
+      xor_buf(i_key, hmac_key, hmac_key.size());
+      xor_buf(o_key, hmac_key, hmac_key.size());
+      }
+   else
+      {
+      xor_buf(i_key, key, length);
+      xor_buf(o_key, key, length);
+      }
+
+   hash->update(i_key);
+   }
+
+/*
+* Clear memory of sensitive data
+*/
+void HMAC::clear() throw()
+   {
+   hash->clear();
+   i_key.clear();
+   o_key.clear();
+   }
+
+/*
+* Return the name of this type
+*/
+std::string HMAC::name() const
+   {
+   return "HMAC(" + hash->name() + ")";
+   }
+
+/*
+* Return a clone of this object
+*/
+MessageAuthenticationCode* HMAC::clone() const
+   {
+   return new HMAC(hash->clone());
+   }
+
+/*
+* HMAC Constructor
+*/
+HMAC::HMAC(HashFunction* hash_in) :
+   MessageAuthenticationCode(hash_in->OUTPUT_LENGTH,
+                             1, 2*hash_in->HASH_BLOCK_SIZE),
+   hash(hash_in)
+   {
+   if(hash->HASH_BLOCK_SIZE == 0)
+      throw Invalid_Argument("HMAC cannot be used with " + hash->name());
+
+   i_key.create(hash->HASH_BLOCK_SIZE);
+   o_key.create(hash->HASH_BLOCK_SIZE);
+   }
+
+}